/*
    wearechat - generic multiplayer game with voip
    Copyright (C) 2025 metamuffin

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, version 3 of the License only.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
#![feature(iter_array_chunks)]
#![allow(clippy::too_many_arguments, clippy::type_complexity)]
pub mod mesh;
pub mod physics;
pub mod vrm;

use anyhow::{Result, anyhow};
use clap::Parser;
use gltf::{Gltf, Node, image::Source, import_buffers, scene::Transform};
use humansize::BINARY;
use image::{ImageReader, codecs::webp::WebPEncoder};
use log::{debug, info};
use mesh::import_mesh;
use physics::import_physics;
use rand::random;
use rayon::iter::{IntoParallelRefIterator, ParallelIterator};
use std::{
    borrow::Cow,
    collections::{BTreeMap, HashMap},
    fs::File,
    io::{Cursor, Read, Write},
    marker::PhantomData,
    net::{SocketAddr, TcpStream},
    path::{Path, PathBuf},
    sync::{Arc, Mutex},
    thread::{self, sleep},
    time::Duration,
};
use vrm::{Vrm, Vrmc};
use weareshared::{
    Affine3A, Vec3A,
    helper::ReadWrite,
    packets::{Data, Object, Packet, Resource},
    resources::{ArmaturePart, EnvironmentPart, Image, LightPart, Prefab},
    store::ResourceStore,
    vec3a,
};

#[derive(Parser)]
pub struct Args {
    address: SocketAddr,
    /// Path(s) to a glTF file, binary or json format
    scene: Vec<PathBuf>,
    /// Send all resources to the server then quit
    #[arg(short, long)]
    push: bool,

    /// Remove all other object from the world
    #[arg(short, long)]
    clear: bool,
    /// Add the object to the world
    #[arg(short, long)]
    add: bool,
    /// Transcode all textures to WebP
    #[arg(short, long)]
    webp: bool,
    /// Add skybox
    #[arg(long)]
    skybox: Option<PathBuf>,
    /// Override prefab name
    #[arg(short, long)]
    name: Option<String>,
    #[arg(short, long)]
    scale: Option<f32>,
    #[arg(short, long)]
    dry_run: bool,
    #[arg(short, long)]
    line_up: bool,

    #[arg(long)]
    use_cache: bool,

    /// Spins the object
    #[arg(long)]
    debug_spin: bool,
    /// Adds a light
    #[arg(long)]
    debug_light: bool,
    /// Wiggles joint index 6
    #[arg(long)]
    debug_armature: bool,
}

fn main() -> Result<()> {
    env_logger::init_from_env("LOG");
    let args = Args::parse();

    let store = if args.use_cache {
        ResourceStore::new_env()?
    } else {
        ResourceStore::new_memory()
    };

    let mut prefabs = Vec::new();
    let texture_cache = Arc::new(Mutex::new(HashMap::new()));

    let mut root_affine = Affine3A::IDENTITY;
    root_affine.matrix3 *= args.scale.unwrap_or(1.);
    root_affine.translation *= args.scale.unwrap_or(1.);

    let mut debug_bone = (0, Affine3A::IDENTITY);

    for scenepath in &args.scene {
        let path_base = scenepath.parent().unwrap();
        let mut gltf = Gltf::from_reader_without_validation(File::open(scenepath)?)?;
        let blob = gltf.blob.take();
        let buffers = import_buffers(&gltf, Some(path_base), blob)?;

        let root = gltf.default_scene().ok_or(anyhow!("no default scene"))?;

        let mut nodes = Vec::new();
        fn traverse<'a>(out: &mut Vec<(Affine3A, Node<'a>)>, node: Node<'a>, trans: Affine3A) {
            let trans = trans * transform_to_affine(node.transform());
            for c in node.children() {
                traverse(out, c, trans);
            }
            out.push((trans, node));
        }

        for node in root.nodes() {
            traverse(&mut nodes, node, root_affine);
        }

        let mut skin_index_to_arm_index = BTreeMap::new();
        let armature = {
            let mut joint_index_to_arm_index = BTreeMap::new();
            let mut name = Vec::new();
            let mut parent_pre_map = Vec::new();
            let mut transform = Vec::new();

            for skin in gltf.skins() {
                for (j_ind, j) in skin.joints().enumerate() {
                    let a_ind = match joint_index_to_arm_index.get(&j.index()) {
                        Some(i) => *i,
                        None => {
                            let a_ind = name.len();
                            // name.push(j.name().unwrap_or("").to_string());
                            name.push(format!("bone{}", a_ind));
                            transform.push(transform_to_affine(j.transform()));
                            parent_pre_map.push(
                                gltf.nodes()
                                    .find(|n| n.children().any(|c| c.index() == j.index()))
                                    .map(|n| n.index()),
                            );

                            joint_index_to_arm_index.insert(j.index(), a_ind);
                            a_ind
                        }
                    };
                    skin_index_to_arm_index.insert((skin.index(), j_ind as u16), a_ind as u32);
                }
            }

            let parent = parent_pre_map
                .into_iter()
                .enumerate()
                .map(|(i, p)| {
                    p.and_then(|i| joint_index_to_arm_index.get(&i).copied())
                        .unwrap_or_else(|| i) as u16
                })
                .collect::<Vec<_>>();

            if let Some(vrm) = gltf.extension_value("VRM") {
                let vrm: Vrm = serde_json::from_value(vrm.clone())?;
                for bone in vrm.humanoid.human_bones {
                    let ind = joint_index_to_arm_index[&bone.node];
                    name[ind] = bone.bone;
                }
            }
            if let Some(vrm) = gltf.extension_value("VRMC_vrm") {
                let vrm: Vrmc = serde_json::from_value(vrm.clone())?;
                for (bname, bone) in vrm.humanoid.human_bones {
                    let ind = joint_index_to_arm_index[&bone.node];
                    name[ind] = bname;
                }
            }

            for (i, (name, tr)) in name.iter().zip(transform.iter()).enumerate() {
                if name == "head" {
                    debug_bone = (i, *tr);
                }
            }

            if !parent.is_empty() {
                Some(store.set(&ArmaturePart {
                    name: Some(name),
                    parent: Some(parent),
                    transform: Some(transform),
                })?)
            } else {
                None
            }
        };

        let mut prefab = nodes
            .par_iter()
            .map(|(trans, node)| {
                let mut prefab = Prefab::default();

                if !node.name().unwrap_or_default().ends_with("-collider") {
                    if let Some(mesh) = node.mesh() {
                        import_mesh(
                            mesh,
                            *trans,
                            &buffers,
                            &store,
                            path_base,
                            node,
                            &mut prefab,
                            &args,
                            &texture_cache,
                            &skin_index_to_arm_index,
                        )?;
                    }
                }
                let (position, _, _) = node.transform().decomposed();
                if let Some(light) = node.light() {
                    let name = node.name().map(|e| e.to_owned());
                    if let Some(name) = &name {
                        info!("adding light {name:?}");
                    } else {
                        info!("adding light");
                    }
                    let emission = Some(Vec3A::from_array(light.color()) * light.intensity());
                    if let Some(e) = emission {
                        debug!("emission is {e}");
                    }
                    prefab.light.push((
                        Vec3A::from_array(position),
                        store.set(&LightPart {
                            emission,
                            name,
                            radius: None,
                        })?,
                    ));
                }
                import_physics(&gltf, *trans, node, &mut prefab, &store, &buffers)?;
                Ok::<_, anyhow::Error>(prefab)
            })
            .reduce(
                || Ok(Prefab::default()),
                |a, b| {
                    let mut a = a?;
                    let b = b?;
                    a.collision.extend(b.collision);
                    a.mesh.extend(b.mesh);
                    a.light.extend(b.light);
                    a.environment = a.environment.or(b.environment);
                    a.name = a.name.or(b.name);
                    Ok(a)
                },
            )?;

        prefab.armature = armature.into_iter().collect();

        if let Some(skybox) = &args.skybox {
            let mut buf = Vec::new();
            File::open(skybox)?.read_to_end(&mut buf)?;
            prefab.environment = Some(store.set(&EnvironmentPart {
                skybox: Some(store.set(&Image(Cow::Owned(buf)))?),
                ..Default::default()
            })?);
        }

        prefab.name = args.name.clone().or(gltf
            .default_scene()
            .and_then(|n| n.name())
            .map(|n| n.to_owned()));

        if args.debug_light {
            prefab.light.push((
                vec3a(5., 5., 5.),
                store.set(&LightPart {
                    name: Some("debug light".to_owned()),
                    emission: Some(vec3a(10., 5., 15.)),
                    radius: Some(0.3),
                })?,
            ));
        }

        prefabs.push(store.set(&prefab)?);
    }

    let mut size = 0;
    store.iter(|_k, len| size += len).unwrap();
    info!(
        "prefab has network size of {}",
        humansize::format_size(size, BINARY)
    );

    if args.dry_run {
        return Ok(());
    }

    let mut sock = TcpStream::connect(args.address)?;
    Packet::Connect(random()).write(&mut sock)?;
    for p in &prefabs {
        Packet::AnnouncePrefab(p.clone()).write(&mut sock)?;
    }
    sock.flush()?;

    let mut obs = Vec::new();
    if args.add {
        for (i, p) in prefabs.iter().enumerate() {
            let ob = Object::new();
            info!("adding object {ob}");
            Packet::Add(ob, p.clone()).write(&mut sock)?;
            if args.line_up {
                Packet::Position(ob, vec3a(i as f32 * 1.2, 0., i as f32 * 0.3), Vec3A::ZERO)
                    .write(&mut sock)?;
            }
            obs.push(ob);
        }
        sock.flush()?;
    }

    if args.debug_spin {
        let ob = obs[0];
        let mut sock2 = sock.try_clone().unwrap();
        thread::spawn(move || {
            let mut x = 0.;
            loop {
                Packet::Position(ob, Vec3A::ZERO, vec3a(0., x * 0.1, 0.))
                    .write(&mut sock2)
                    .unwrap();
                sock2.flush().unwrap();
                x += 0.1;
                sleep(Duration::from_millis(50));
            }
        });
    }
    if args.debug_armature {
        let ob = obs[0];
        let mut sock2 = sock.try_clone().unwrap();
        thread::spawn(move || {
            let mut x = 0f32;
            loop {
                let a = Affine3A::IDENTITY
                    * Affine3A::from_rotation_x(x.cos() * 0.3)
                    * Affine3A::from_rotation_y(x.sin() * 0.5)
                    * debug_bone.1;
                Packet::Pose(ob, vec![(debug_bone.0 as u16, a)])
                    .write(&mut sock2)
                    .unwrap();
                sock2.flush().unwrap();
                x += 0.2;
                sleep(Duration::from_millis(50));
            }
        });
    }

    if args.push {
        if args.use_cache {
            return Ok(());
        }
        store.iter(|k, _| {
            Packet::RespondResource(k, Data(store.get_raw(k).unwrap().unwrap()))
                .write(&mut sock)
                .unwrap();
        })?;
        sock.flush()?;
    } else {
        loop {
            let packet = Packet::read(&mut sock)?;
            match packet {
                Packet::RequestResource(hash) => {
                    if let Some(d) = store.get_raw(hash)? {
                        Packet::RespondResource(hash, Data(d)).write(&mut sock)?;
                        sock.flush()?;
                    }
                }
                Packet::Add(ob_a, _) => {
                    if args.clear && !obs.contains(&ob_a) {
                        info!("removing object {ob_a}");
                        Packet::Remove(ob_a).write(&mut sock)?;
                        sock.flush()?;
                    }
                }
                _ => (),
            }
        }
    }
    Ok(())
}

pub type TextureCache = Arc<Mutex<HashMap<String, Resource<Image<'static>>>>>;
fn load_texture(
    name: &str,
    store: &ResourceStore,
    path: &Path,
    buffers: &[gltf::buffer::Data],
    source: &Source,
    webp: bool,
    texture_cache: &TextureCache,
) -> Result<Resource<Image<'static>>> {
    let (mut image, uri) = match source {
        gltf::image::Source::View { view, mime_type } => {
            debug!("{name} texture is embedded and of type {mime_type:?}");
            let buf =
                &buffers[view.buffer().index()].0[view.offset()..view.offset() + view.length()];
            (Image(Cow::Borrowed(buf)), None)
        }
        gltf::image::Source::Uri {
            uri,
            mime_type: Some(mime_type),
        } => {
            debug!("{name} texture is {uri:?} and of type {mime_type:?}");
            if let Some(res) = texture_cache.lock().unwrap().get(*uri) {
                return Ok(res.to_owned());
            }
            let path = path.join(uri);
            let mut buf = Vec::new();
            File::open(path)?.read_to_end(&mut buf)?;
            (Image(buf.into()), Some(uri.to_string()))
        }
        gltf::image::Source::Uri {
            uri,
            mime_type: None,
        } => {
            debug!("{name} texture is {uri:?} and has no type");
            if let Some(res) = texture_cache.lock().unwrap().get(*uri) {
                return Ok(res.to_owned());
            }
            let path = path.join(uri);
            let mut buf = Vec::new();
            File::open(path)?.read_to_end(&mut buf)?;
            (Image(buf.into()), Some(uri.to_string()))
        }
    };

    if webp {
        let mut image_out = Vec::new();

        let len = image.0.len();
        ImageReader::new(Cursor::new(image.0))
            .with_guessed_format()?
            .decode()?
            .write_with_encoder(WebPEncoder::new_lossless(&mut image_out))?;
        debug!("webp encode: {len} -> {}", image_out.len());
        image = Image(Cow::Owned(image_out));
    }
    let res = Resource(store.set(&image)?.0, PhantomData);
    if let Some(uri) = uri {
        texture_cache.lock().unwrap().insert(uri, res.clone());
    }
    Ok(res)
}

pub fn transform_to_affine(trans: Transform) -> Affine3A {
    let mat = trans.matrix();
    Affine3A::from_cols_array_2d(&[
        [mat[0][0], mat[0][1], mat[0][2]],
        [mat[1][0], mat[1][1], mat[1][2]],
        [mat[2][0], mat[2][1], mat[2][2]],
        [mat[3][0], mat[3][1], mat[3][2]],
    ])
}